The invention relates to a method of detecting enterogastric reflux and to apparatus for implementing said method.
Enterogastric reflux, i.e. the reflux of bile from the duodenum into the stomach, is an important phenomenon in gastroenterology. It has, in fact, been found that the presence of bile in the gastric juice can have a harmful effect on the esophageal mucosa. Furthermore, although it has not yet been shown that the said reflux has a manifest effect on the nonoperated stomach, it has been demonstrated that erythema and foveolate hyperplasia of the gastric mucosa correlate with enterogastric reflux after partial gastrectomy. In addition, enterogastric reflux can be responsible for a number of dyspeptic syndromes of uncertain classification. It is therefore necessary to perform in-vivo tests to determine whether bile is present in the gastric juice of the patient.
At present, the most widely used method of detecting enterogastric reflux is based on measurements of the acidity of the gastric juice. It is well-known, in fact, that gastric juice--under normal conditions--has a pH value of between 2 and 3, whereas the pH of the bile is approximately 7. A reflux of bile into the stomach therefore raises the pH of the gastric juice since it reduces its acidity. In the current method, therefore, a glass electrode capable of detecting the concentration of hydrogen ions in the gastric juice is introduced into the stomach of the patient for the purpose of effecting continuous monitoring--over a period of up to a whole day--of the acidity of the gastric juice, thereby obtaining indirect evidence of the presence of enterogastric reflux. This method has numerous limitations and disadvantages.
The need to apply a voltage, albeit a very small one, to the probe necessitates the use of expensive equipment to ensure that specific safety standards are met.
In addition, the findings are not reliable: if the sensitive part of the electrode comes to rest on the internal mucosa of the stomach, this will be sufficient to give a false indication of reflux. This is because the mucosa is kept at a pH of approximately 7, i.e. in a neutral condition. If the probe touches these tissues, it will automatically register a rise in pH, which may be erroneously interpreted as a sign of enterogastric reflux, whereas such reflux may not have taken place.
Furthermore, under some conditions (partial gastrectomy, atrophic gastritis, etc.) in which the pH of the gastric juice is almost neutral, enterogastric reflux may not be detected by monitoring the pH value.
As mentioned above, the monitoring may last for many hours. During the period of time that the probe is in the patient's stomach it is necessary to give the patient food. The ingestion of food brings about changes in the acidity of the gastric juices, making it necessary to disregard the measurements taken over a specific period of time (approximately one and a half hours) after the food is consumed.
The method currently in use also does not permit the reflux of bile into the esophagus to be detected, since the pH value in the esophagus is close to 7 and the reflux of bile therefore has no effect on this pH value.
Finally, since the normal pH values of the gastric juice and the bile do not remain perfectly constant, the current method of detection does not permit quantitative, but only qualitative measurement of the reflux.